Severe thunderstorms are possible across much of Tennessee, including the Cumberland Plateau, on Thursday afternoon, according to the National Weather Service.
In a Hazardous Weather Outlook published Wednesday afternoon, the NWS’s Morristown weather forecast office — which covers Scott County — said that “a few severe thunderstorms” are possible on Thursday from the afternoon through the night, with the highest chances of severe weather existing near the Cumberland Plateau.
“The main threat will be damaging thunderstorm winds,” the NWS said in the HWO. “However, a low risk exists for tornadoes and hail with the strongest thunderstorms. Always have multiple ways to receive warning information.”
It’s been just nine days since a supercell spawned 10 tornadoes across Middle Tennessee and the Cumberland Plateau, including a deadly twister that killed 18 people in Putnam County, on a night when the tornado risk was thought to be near zero.
In a forecast discussion Wednesday afternoon, meteorologists at NWS-Morristown said that the severe weather potential for Thursday is “complex,” with the potential dependent on sun and cloud cover during the day. Meteorologists explained that while there is the potential for supercell storm structures to develop while the atmosphere is unstable on Wednesday evening, it remains uncertain whether such storms will initiate before more stable air moves in.
“While the threat of tornadoes is low, the threat will exist with any supercell that develops within close proximity to the warm front, especially across the Cumberland Plateau and areas generally north and west of the Knoxville area,” the NWS said, adding that other threats include damaging wind and hail.
Just to the west, the NWS’s weather forecast office in Nashville — which covers Fentress County — said in its own Hazardous Weather Outlook that “damaging winds are the most likely hazard, but a tornado cannot be ruled out. Localized large hail may occur.”
Additionally, NWS-Nashville said, “Locally heavy downpours are expected Thursday evening and may cause brief flooding of streets and low lying areas.”
In its forecast discussion, NWS-Nashville meteorologists said that the primary threat during the afternoon hours on Thursday would be gusty winds and some hail, though an isolated tornado could not be ruled out. Later in the evening, they added, wind shear would increase as the cold front approaches the mid-state area. “It will all depend on the storm mode in the late afternoon and evening timeframe, but damaging winds, hail, and even a few tornadoes are not out of the question,” the NWS said in the discussion. “It appears right now that the late afternoon through late evening timeframe will be the best chance at severe thunderstorms, again with the potential for damaging winds, hail, and even a few tornadoes.”
The severe weather threat is expected to diminish as the night progresses.
NOAA’s Storm Prediction Center in Norman, Okla. has outlined an “enhanced risk area” for severe weather across northern parts of West Tennessee and much of Middle Tennessee, extending further north into western Kentucky, as well as back into the Missouri boot heel region. The northern Cumberland Plateau, along with much of the rest of Tennessee, is in a “slight risk area” for severe storms.
“Severe thunderstorms with tornadoes, large hail and wind damage are likely across parts of the mid Mississippi, Ohio and Tennessee Valleys (Thursday) afternoon and evening,” the SPC said in its outlook.”
To the west of the Cumberland Plateau, where the severe weather risk was deemed highest, the SPC said that significant tornadoes would be possible. Forecast soundings near Paducah, Ky. indicated conditions that would “be favorable for supercells and tornadoes,” forecasters said, with a threat for significant tornadoes. “A threat for large hail and wind damage will also be associated with supercells,” the outlook stated.